<!DOCTYPE html>
<html>
<head>
    <title>Overlay</title>
    <meta charset="UTF-8">
    <title>WMS GetFeatureInfo (Image Layer)</title>
    <script src="OpenLayers4.3.1/ol.js"></script>
    <link rel="stylesheet" href="OpenLayers4.3.1/ol.css" type="text/css">
    <script src="https://code.jquery.com/jquery-2.2.3.min.js"></script>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
    <style>
        #marker {
            width: 20px;
            height: 20px;
            border: 1px solid #088;
            border-radius: 10px;
            background-color: #0FF;
            opacity: 0.5;
        }
        #vienna {
            text-decoration: none;
            color: white;
            font-size: 11pt;
            font-weight: bold;
            text-shadow: black 0.1em 0.1em 0.2em;
        }
        .popover-content {
            min-width: 180px;
        }
    </style>
</head>
<body>
<div id="map" class="map"></div>
<div style="display: none;">
    <!-- Clickable label for Vienna -->
    <a class="overlay" id="vienna" target="_blank" href="http://en.wikipedia.org/wiki/Vienna">Vienna</a>
    <div id="marker" title="Marker"></div>
    <!-- Popup -->
    <div id="popup" title="Welcome to OpenLayers"></div>
</div>
<script>
    var layer = new ol.layer.Tile({
        source: new ol.source.OSM()
    });

    var map = new ol.Map({
        layers: [layer],
        target: 'map',
        view: new ol.View({
            center: [0, 0],
            zoom: 2
        })
    });

    var pos = ol.proj.fromLonLat([16.3725, 48.208889]);

    // Vienna marker
    var marker = new ol.Overlay({
        position: pos,
        positioning: 'center-center',
        element: document.getElementById('marker'),
        stopEvent: false
    });
    map.addOverlay(marker);

    // Vienna label
    var vienna = new ol.Overlay({
        position: pos,
        element: document.getElementById('vienna')
    });
    map.addOverlay(vienna);

    // Popup showing the position the user clicked
    var popup = new ol.Overlay({
        element: document.getElementById('popup')
    });
    map.addOverlay(popup);

    map.on('click', function(evt) {
        var element = popup.getElement();
        var coordinate = evt.coordinate;
        var hdms = ol.coordinate.toStringHDMS(ol.proj.transform(
                coordinate, 'EPSG:3857', 'EPSG:4326'));

        $(element).popover('destroy');
        popup.setPosition(coordinate);
        // the keys are quoted to prevent renaming in ADVANCED mode.
        $(element).popover({
            'placement': 'top',
            'animation': false,
            'html': true,
            'content': '<p>The location you clicked was:</p><code>' + hdms + '</code>'
        });
        $(element).popover('show');
    });
</script>
</body>
</html>